vlc_arrays.h

mips版本的VLC视频服务器

    memset( p_array, 0, sizeof(vlc_array_t) );
}

static inline vlc_array_t * vlc_array_new( void )
{
    vlc_array_t * ret = (vlc_array_t *)malloc( sizeof(vlc_array_t) );
    if( ret ) vlc_array_init( ret );
    return ret;
}

static inline void vlc_array_destroy( vlc_array_t * p_array )
{
    if( !p_array )
        return;
    vlc_array_clear( p_array );
    free( p_array );
}


/* Read */
static inline int
vlc_array_count( vlc_array_t * p_array )
{
    return p_array->i_count;
}

static inline void *
vlc_array_item_at_index( vlc_array_t * p_array, int i_index )
{
    return p_array->pp_elems[i_index];
}

static inline int
vlc_array_index_of_item( vlc_array_t * p_array, void * item )
{
    int i;
    for( i = 0; i < p_array->i_count; i++)
    {
        if( p_array->pp_elems[i] == item )
            return i;
    }
    return -1;
}

/* Write */
static inline void
vlc_array_insert( vlc_array_t * p_array, void * p_elem, int i_index )
{
    TAB_INSERT_CAST( (void **), p_array->i_count, p_array->pp_elems, p_elem, i_index );
}

static inline void
vlc_array_append( vlc_array_t * p_array, void * p_elem )
{
    vlc_array_insert( p_array, p_elem, p_array->i_count );
}

static inline void
vlc_array_remove( vlc_array_t * p_array, int i_index )
{
    if( i_index >= 0 )
    {
        if( p_array->i_count > 1 )
        {
            memmove( p_array->pp_elems + i_index,
                     p_array->pp_elems + i_index+1,
                     ( p_array->i_count - i_index - 1 ) * sizeof( void* ) );
        }
        p_array->i_count--;
        if( p_array->i_count == 0 )
        {
            free( p_array->pp_elems );
            p_array->pp_elems = NULL;
        }
    }
}


/************************************************************************
 * Dictionaries
 ************************************************************************/

/* This function is not intended to be crypto-secure, we only want it to be
 * fast and not suck too much. This one is pretty fast and did 0 collisions
 * in wenglish's dictionary.
 */
static inline uint64_t DictHash( const char *psz_string, int hashsize )
{
    uint64_t i_hash = 0;
    if( psz_string )
    {
        while( *psz_string )
        {
            i_hash += *psz_string++;
            i_hash += i_hash << 10;
            i_hash ^= i_hash >> 8;
        }
    }
    return i_hash % hashsize;
}

typedef struct vlc_dictionary_entry_t
{
    char *   psz_key;
    void *   p_value;
    struct vlc_dictionary_entry_t * p_next;
} vlc_dictionary_entry_t;

typedef struct vlc_dictionary_t
{
    int i_size;
    vlc_dictionary_entry_t ** p_entries;
} vlc_dictionary_t;

static void * const kVLCDictionaryNotFound = NULL;

static inline void vlc_dictionary_init( vlc_dictionary_t * p_dict, int i_size )
{
    p_dict->p_entries = NULL;

    if( i_size > 0 )
    {
        p_dict->p_entries = (vlc_dictionary_entry_t **)calloc( i_size, sizeof(*p_dict->p_entries) );
        if( !p_dict->p_entries )
            i_size = 0;
    }
    p_dict->i_size = i_size;
}

static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict,
                                         void ( * pf_free )( void * p_data, void * p_obj ),
                                         void * p_obj )
{
    if( p_dict->p_entries )
    {
        for( int i = 0; i < p_dict->i_size; i++ )
        {
            vlc_dictionary_entry_t * p_current, * p_next;
            p_current = p_dict->p_entries[i];
            while( p_current )
            {
                p_next = p_current->p_next;
                if( pf_free != NULL )
                    ( * pf_free )( p_current->p_value, p_obj );
                free( p_current->psz_key );
                free( p_current );
                p_current = p_next;
            }
        }
        free( p_dict->p_entries );
        p_dict->p_entries = NULL;
    }
    p_dict->i_size = 0;
}



static inline void *
vlc_dictionary_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
{
    if( !p_dict->p_entries )
        return kVLCDictionaryNotFound;

    int i_pos = DictHash( psz_key, p_dict->i_size );
    vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];

    if( !p_entry )
        return kVLCDictionaryNotFound;

    /* Make sure we return the right item. (Hash collision) */
    do {
        if( !strcmp( psz_key, p_entry->psz_key ) )
            return p_entry->p_value;
        p_entry = p_entry->p_next;
    } while( p_entry );

    return kVLCDictionaryNotFound;
}

static inline int
vlc_dictionary_keys_count( const vlc_dictionary_t * p_dict )
{
    vlc_dictionary_entry_t * p_entry;
    int i, count = 0;

    if( !p_dict->p_entries )
        return 0;

    for( i = 0; i < p_dict->i_size; i++ )
    {
        for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next ) count++;
    }
    return count;
}

static inline char **
vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
{
    vlc_dictionary_entry_t * p_entry;
    char ** ppsz_ret;
    int i, count = vlc_dictionary_keys_count( p_dict );

    ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));

    count = 0;
    for( i = 0; i < p_dict->i_size; i++ )
    {
        for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
            ppsz_ret[count++] = strdup( p_entry->psz_key );
    }
    ppsz_ret[count] = NULL;
    return ppsz_ret;
}

static inline void
__vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key,
                         void * p_value, bool rebuild )
{
    if( !p_dict->p_entries )
        vlc_dictionary_init( p_dict, 1 );

    int i_pos = DictHash( psz_key, p_dict->i_size );
    vlc_dictionary_entry_t * p_entry;

    p_entry = (vlc_dictionary_entry_t *)malloc(sizeof(*p_entry));
    p_entry->psz_key = strdup( psz_key );
    p_entry->p_value = p_value;
    p_entry->p_next = p_dict->p_entries[i_pos];
    p_dict->p_entries[i_pos] = p_entry;
    if( rebuild )
    {
        /* Count how many items there was */
        int count;
        for( count = 1; p_entry->p_next; count++ )
            p_entry = p_entry->p_next;
        if( count > 3 ) /* XXX: this need tuning */
        {
            /* Here it starts to be not good, rebuild a bigger dictionary */
            struct vlc_dictionary_t new_dict;
            int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
            int i;
            vlc_dictionary_init( &new_dict, i_new_size );
            for( i = 0; i < p_dict->i_size; i++ )
            {
                p_entry = p_dict->p_entries[i];
                while( p_entry )
                {
                    __vlc_dictionary_insert( &new_dict, p_entry->psz_key,
                                             p_entry->p_value,
                                             false /* To avoid multiple rebuild loop */);
                    p_entry = p_entry->p_next;
                }
            }

            vlc_dictionary_clear( p_dict, NULL, NULL );
            p_dict->i_size = new_dict.i_size;
            p_dict->p_entries = new_dict.p_entries;
        }
    }
}

static inline void
vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
{
    __vlc_dictionary_insert( p_dict, psz_key, p_value, true );
}

static inline void
vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key,
                                     void ( * pf_free )( void * p_data, void * p_obj ),
                                     void * p_obj )
{
    if( !p_dict->p_entries )
        return;

    int i_pos = DictHash( psz_key, p_dict->i_size );
    vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
    vlc_dictionary_entry_t * p_prev;

    if( !p_entry )
        return; /* Not found, nothing to do */

    /* Hash collision */
    p_prev = NULL;
    do {
        if( !strcmp( psz_key, p_entry->psz_key ) )
        {
            if( pf_free != NULL )
                ( * pf_free )( p_entry->p_value, p_obj );
            if( !p_prev )
                p_dict->p_entries[i_pos] = p_entry->p_next;
            else
                p_prev->p_next = p_entry->p_next;
            free( p_entry->psz_key );
            free( p_entry );
            return;
        }
        p_prev = p_entry;
        p_entry = p_entry->p_next;
    } while( p_entry );

    /* No key was found */
}

#endif